• 제목/요약/키워드: early maturity

검색결과 542건 처리시간 0.023초

양생온도 변화에 따른 고강도 모르터의 자기수축 특성 (Autogenous Shrinkage of High Strength Mortar According to the Curing Temperature Variation)

  • 송일범;이일선;백대현;한민철;한천구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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    • pp.83-85
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    • 2010
  • This study, by analyzing autogenous shrinkage of high-strength mortar according to changes of curing temperature, examined whether or not predictive autogenous shrinkage by an accumulated temperature method can be calculated. As a result, it could be known that dependency of autogenous shrinkage on temperature can be examined, but the autogenous shrinkage amount according to accumulated temperature was similar before and after the early $100 ^{\circ}D{\cdot}D$ and, after that, the difference in shrinkage amount by curing temperature was large.

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늦부모됨에 관한 탐색적 고찰 (An Exploratory Study on Late Parenthood)

  • 김용미
    • 가정과삶의질연구
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    • 제23권6호
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    • pp.167-178
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    • 2005
  • The purpose of this study was to investigate various assects of late parenthood among Korean parents, including motivation, emotional response, advantages and disadvantages of late parenthood, intimacy, and effects on child. Subjects were IS mothers who gave birth after 35 years old for both mother and father. The study was conducted by means of a questionnaire and an in-depth interview. The most significant reason for late parenthood was found to be a son preference. brothers of the only could expressed very special emotional responses toward the child, compared to those who gave a birth to the second or the third child after 35. Respondents identified advantages and disadvantages of late parenthood in terms of child rare attitudes, maturity, financial conditions, and physical strength. However, most of the respondents would not recommend late parenthood to others. Directions for future research were given in terms of subjects of study, such as parents from rural area, working class, and wide range of ages.

유아기 감성지능 발달 경향성 연구 (Age Differences in Emotional Intelligence: The Emotional Intelligence Test for Children)

  • 이승은
    • 아동학회지
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    • 제26권6호
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    • pp.29-43
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    • 2005
  • Emotional intelligence is a relatively new concept and little research to date has examined age differences. In order to examine developmental patterns in emotional intelligence(En, the Emotional Intelligence Test for Children(EITC, Lee, 2003) was administered to 367 children, 4- to 8-years of age. Data were analyzed by Multivariate Analysis of Variance(MANOVA) and post hoc univariate analyses of variables. Results showed significant differences by age in total and sub-total scores of EITC. When the means of test scores were presented graphically as developmental curves, EI totals and sub-scores showed the increases in EI that occurred with increased maturity. Additional research is needed to verify developmental models of EI and to explore which factors have an effect on EI.

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전자무역 성과평가 체계에 관한 연구 (A Study on Global e-Trade Performance Evaluation Framework)

  • 김학민;김종철
    • 통상정보연구
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    • 제9권2호
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    • pp.231-253
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    • 2007
  • This paper intends to develop an performance evaluation framework of e-trade. The Korea e-trade has been largely attracting many research communities because it brings about e-trade platform which is happening at the early stage of information system maturity. It is true that many research works have been focusing on development issues in e-trade but not much works have been done in e-trade performance study. This paper suggests an e-trade performance framework based on both field and literatures surveys. In addition, an factor analysis model has been introduced to determine that the suggested factors are empirically supporting the hypotheses in the model. Since this paper is opening up many research issues in e-trade performance study many research group could participate in this research area.

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Highly Complex Green Parts in Excellent Quality

  • Nies, Norbert;Peters, Detlef
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.747-749
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    • 2006
  • SMS Meer GmbH, formerly Mannesmann and today part of the SMS Group, has been building powder presses since the early 1950s. The patents developed here in this field have long since documented the pioneering work carried out for the PM industry. The paper focuses on the challenge of reconciling the contradictory demands in the production of highly complex and crack-free PM parts. The process employed with the patented Controlled Punch Adapter (CPA) [1] counters possible cracking reliably and directly at the source. In this way is it possible to develop new and highly complex parts to series production maturity in a minimum of time even without simulation of the press cycle [2]. The quality data achieved in the production series, almost 100% crack and micro crack-free green parts with optimum density distribution over all press levels is unrivalled and thus gives the user a clear lead over the competition.

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내한촉진제를 이용한 시멘트 모르터의 동결 및 강도특성에 관한 연구 (A Study on the Freezing and Strength Properties of Cement Mortar using Accelerator for Freezing Resistance)

  • 박상준;김동석;원철;이상수;김영진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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    • pp.1267-1272
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    • 2000
  • When fresh concrete is exposed to low temperature, the concrete may suffer frost damage due to freezing at early ages and strength development may be delayed. These are problems on cold weather concrete. One of the solution methods for resolving these problems has been to reduce the freezing temperature of concrete by the use of chemical admixtures called Accelerators for freezing resistance. Therefore, in this study, we executed freezing temperature of mortar, setting and strength properties with using water reducing accelerator and accelerators for freezing resistance which are producted internationally. As a result of this experiment, the freezing temperature of mortar is lower and the setting property is promoted when the admixing content of accelerators for freezing resistance is increased. Moreover, the compressive strength of mortar used accelerators for freezing resistance represented the result which is similar with result of analysis of compressive strength increase with using logistic curve formula, but in the case of plain and using water reducing accelerator, there is no relation between logistic curve formula, maturity and compressive strength.

비용, 일정 및 기술적 성과를 고려한 통합 계획수립 프로세스 구현 방안 (Integrated Planning Process Implementation Method Based on the Cost, Schedule, and Technical Performance)

  • 유이주;박영원
    • 한국군사과학기술학회지
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    • 제10권3호
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    • pp.100-108
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    • 2007
  • The purpose of the research is to propose an integrated project planning process and its implementation method. Although there is increasing interest in the application of the Earned Value Management(EVM) method in the project management area, the progress and maturity of the technical performance have not been included in assessing the Earned Value. The main concept of the planning process is to use cost, schedule, as well as the technical performance in the assessment of the Earned Value Management for Military R&D project management practices. The resulting process can enhance the efficiency of the project work by eliminating the currently duplicated activities between traditional project planning process and the newly implemented Earned Value Management process and by shortening the early planning process duration of projects adopting EVM practices.

Conduits for Coronary Bypass: Vein Grafts

  • Barner, Hendrick B.;Farkas, Emily A.
    • Journal of Chest Surgery
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    • 제45권5호
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    • pp.275-286
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    • 2012
  • The saphenous vein has been the principal conduit for coronary bypass grafting from the beginning, circa 1970. This report briefly traces this history and concomitantly presents one surgeons experience and personal views on use of the vein graft. As such it is not exhaustive but meant to be practical with a modest number of references. The focus is that of providing guidance and perspective which may be at variance with that of others and recognizing that there may be many ways to accomplish the task at hand. Hopefully the surgeon in training/early career may find this instructive on the journey to surgical maturity.

IoT센서를 이용한 고로슬래그 혼입 콘크리트의 압축강도 예측 시스템 개발에 관한 기초 연구 (A Basic Study on the Development of Compressive Strength Prediction System for Blast Furnace Slag Contained Concrete using IoT Sensor)

  • 김한솔;장종민;민태범;이한승
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2020년도 봄 학술논문 발표대회
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    • pp.58-59
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    • 2020
  • The change of temperature and humidity in early-age concrete has a great influence on the durability of the structure. In this study, a reliable wireless sensor network system and a concrete embedded type Compressive strength prediction sensor were designed using the Arduino platform. The accuracy of the compressive strength prediction sensor was verified through a mock-up experiment, and it was confirmed that the experiment had sufficient accuracy to be used in the field environment.

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남부지역 논의 밀 이모작에서 하계 곡실작물 도입의 적합성 (Compatibility of Double Cropping of Winter Wheat - Summer Grain Crops in Paddy Field of Southern Korea)

  • 서종호;황정동;오성환
    • 한국작물학회지
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    • 제66권1호
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    • pp.18-28
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    • 2021
  • 남부지역 논에서 식량작물을 최대로 생산하기 위해 밀양시 국립식량과학원 시험포장에서 2015~2018년의 4년 동안 겨울밀-벼, 겨울밀-콩 및 겨울밀-곡실용옥수수의 이모작 체계의 생육기간 및 생산성을 비교하였다. 밀의 수확적기는 6월 중순으로 하작물은 6월 하순에 파종(이앙)이 가능하였다. 벼의 6월 하순 이앙 시 안전출수와 벼의 수량성 확보에는 지장이 없었지만 가을에 성숙기가 늦어 뒷그루 밀 파종에는 지장이 많았으며, 특히 중만생종 벼의 경우 수확기가 11월 상순으로 늦추어져 밀의 적기파종이 어려웠다. 콩은 6월 하순이 파종적기이므로 작기상 큰 문제가 없었으며 성숙기도 10월 중순으로 11월 상순의밀 파종에 큰 무리가 없었다. 곡실용옥수수는 6월 하순 파종 시 성숙기가 가장 빨라 밀과의 이모작에서 작기상 가장 유리하였다. 겨울밀-하작물 이모작에서 밀은 콩과 곡실용옥수수 후작에서는 안정적인 수량성을 얻을 수 있었지만 벼의 후작에서는 강우가 많은 해에는 수량이 감소할 위험성이 있었다. 벼, 콩, 곡실용옥수수의 수량성은 각각 600, 350, 800 kg/10a로 높은 수량성 확보가 가능하였고 중생종과 중만생종간의 수량성에 큰 차이를 보이지 않아 중생종이 만생종보다 이모작에 유리하였다. 토양 물리성에서도 콩과 옥수수 등 밭작물의 도입 시 물리성이 좋아지는 것으로 나타났다. 따라서 남부지역 논에서 밀-콩/곡실용옥수수 이모작은 작기 연결성 및 토양개선, 소득성(콩)에서 밀-벼 이모작보다 우수한 것으로 나타났다.